Revert "USB: don't explicitly reenable root-hub status interrupts"

This reverts commit e872154921a6b5256a3c412dd69158ac0b135176.

Andrey Borzenkov reports that it resulted in a totally hung machine for
him when loading the OHCI driver.  Extensive netconsole capture with
SysRq output shows that modprobe gets stuck in ohci_hub_status_data()
when probing and enabling the OHCI controller, see for example

	http://lkml.org/lkml/2008/7/5/236

for an analysis.

The problem appears to be an interrupt flood triggered by the commit
that gets reverted, and Andrey confirmed that the revert makes things
work for him again.

Reported-and-tested-by: Andrey Borzenkov <arvidjaar@mail.ru>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: David Brownell <david-b@pacbell.net>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/drivers/usb/host/u132-hcd.c b/drivers/usb/host/u132-hcd.c
index f29307405bb3..9b6323f768b2 100644
--- a/drivers/usb/host/u132-hcd.c
+++ b/drivers/usb/host/u132-hcd.c
@@ -2934,6 +2934,16 @@ static int u132_start_port_reset(struct usb_hcd *hcd, unsigned port_num)
                 return 0;
 }
 
+static void u132_hub_irq_enable(struct usb_hcd *hcd)
+{
+        struct u132 *u132 = hcd_to_u132(hcd);
+        if (u132->going > 1) {
+                dev_err(&u132->platform_dev->dev, "device has been removed %d\n"
+                        , u132->going);
+        } else if (u132->going > 0)
+                dev_err(&u132->platform_dev->dev, "device is being removed\n");
+}
+
 
 #ifdef CONFIG_PM
 static int u132_bus_suspend(struct usb_hcd *hcd)
@@ -2985,6 +2995,7 @@ static struct hc_driver u132_hc_driver = {
         .bus_suspend = u132_bus_suspend,
         .bus_resume = u132_bus_resume,
         .start_port_reset = u132_start_port_reset,
+        .hub_irq_enable = u132_hub_irq_enable,
 };
 
 /*